Left: Developers have shown interest in building housing tracts in areas of Cleveland National Forest. Right: A housing development in Rancho Santa Margarita.
Orange County has more than 3,000 people per square mile, making it one of the most densely populated areas in the country. Amid the suburban sprawl, there are still thousands of acres of open space known as "the canyons."
KPCC's Ed Joyce says, despite apparent protections, the scenic region is under threat of development.